You wouldn't build a house without a blueprint, right? The same should go for building UML software. Use Lucidchart to create free online UML diagrams that . UMLet is a free, open-source UML tool with a simple user interface: draw UML diagrams fast, build sequence and activity diagrams from plain text, export . draw.io is free online diagram software for making flowcharts, process diagrams, org charts, UML, ER and network diagrams. A sophisticated software modeler for agile and concise modeling . Compatible with UML 2.x standard metamodel and diagrams: Class, Object, Use Case, . Visual Paradigm Community Edition - A Free UML Tool. A full-featured, free UML software for visual modeling with UML 2.x diagrams. Previous Slide◁︎ FREE Online UML tool for UML Diagrams. Draw UML Diagrams online for free. Try the FREE web based UML Drawing tool. No Ad, no limited number of shape . SmartDraw helps you plan software projects with the help of UML diagrams. Start with the exact UML template you need. SmartDraw has templates for class . I also recommend Visual Paradigm Online Express Edition. Personally I think it's the best free UML drawing tool. By using VP Online Express Edition, you can: . This view includes sequence diagrams, activity diagrams and state machine diagrams. UML models can be exchanged among UML tools by using the XML .